Supabase + Ark

Replace Supabase’s default email with Ark in under 2 minutes. Get higher deliverability, remove rate limits, and track every auth email.

Why switch from Supabase’s default email? Supabase’s built-in SMTP has strict rate limits and only sends to project team members unless you configure a custom provider. Ark removes these limits and adds delivery tracking.

1-Click Setup (Recommended)

The fastest way to connect Supabase to Ark:

Open Ark Dashboard

Go to arkhq.io/org/integrations in your Ark dashboard.

Click Connect to Supabase

Click the green Connect to Supabase button. You’ll be redirected to Supabase to authorize Ark.

Authorize Access

Select Project & Configure

Choose which Supabase project to connect, enter your sender email and name, then click Connect Project.

Done! Ark automatically creates dedicated SMTP credentials and configures your Supabase project. All auth emails now route through Ark.

Managing multiple projects? You can connect multiple Supabase projects from the same Ark organization. Each gets its own dedicated credentials for easy tracking.

Manual Setup (5 minutes)

Get Your Ark Credentials

Go to arkhq.io/org/credentials and create a new credential if you don’t have one.You’ll need:

Username: Your credential name (e.g., acme/production)
Key: Your credential key (this is your SMTP password)

Verify Your Sending Domain

Supabase auth emails need to come from your domain. If you haven’t already:

Go to arkhq.io/org/domains
Add your domain (e.g., yourdomain.com)
Add the DNS records shown
Wait for verification (usually under 5 minutes)

Domain Setup Guide

Detailed DNS configuration instructions

Configure Supabase SMTP

In your Supabase project dashboard:

Go to Authentication → Email → SMTP Settings
Toggle Enable Custom SMTP to ON
Enter these settings:

Setting	Value
Host	`smtp.arkhq.io`
Port	`587`
Username	Your credential (e.g., `acme/production`)
Password	Your credential key
Sender email	`[email protected]`
Sender name	Your app name

Click Save

Send a Test Email

Trigger a test by:

Creating a new user in Supabase Auth
Or using the password reset flow

Check your inbox. The email should arrive within seconds and show as “Delivered” in your Ark dashboard.

Done! All Supabase auth emails now route through Ark with full delivery tracking.

What Changes

Before (Supabase Default)	After (Ark)
Strict rate limits	No limit (pay per email)
Only sends to team members	Sends to any address
No delivery tracking	Full tracking in dashboard
Generic sender reputation	Your domain’s reputation
No webhook notifications	Real-time delivery events

Configuration Reference

SMTP Settings

Host: smtp.arkhq.io
Port: 587 (STARTTLS) or 465 (Implicit TLS)
Username: your-org/credential-name
Password: your-credential-key
Encryption: TLS/STARTTLS

Recommended Sender Addresses

Email Type	Suggested Address
Auth emails (default)	`[email protected]`
Transactional	`[email protected]`
Notifications	`[email protected]`

Use a subdomain like mail.yourdomain.com if you want to separate your transactional email reputation from your main domain.

Supabase Auth Email Types

Ark handles all Supabase authentication emails:

Email Type	Triggered By
Confirmation	User signs up
Password Reset	User requests password reset
Magic Link	Passwordless login
Email Change	User changes email address
Invite	Admin invites new user
Reauthentication	Sensitive action requires re-verification

All emails use your custom templates configured in Supabase. Ark delivers them—it doesn’t modify content.

Self-Hosted Supabase

For self-hosted Supabase instances, configure SMTP in your docker-compose.yml or environment:

# docker-compose.yml
services:
  supabase-auth:
    environment:
      GOTRUE_SMTP_HOST: smtp.arkhq.io
      GOTRUE_SMTP_PORT: 587
      GOTRUE_SMTP_USER: your-org/production
      GOTRUE_SMTP_PASS: your-credential-key
      GOTRUE_SMTP_ADMIN_EMAIL: [email protected]
      GOTRUE_MAILER_AUTOCONFIRM: false

Or via environment variables:

GOTRUE_SMTP_HOST=smtp.arkhq.io
GOTRUE_SMTP_PORT=587
GOTRUE_SMTP_USER=your-org/production
GOTRUE_SMTP_PASS=your-credential-key
GOTRUE_SMTP_ADMIN_EMAIL=[email protected]

Rate Limits

Supabase Side

After connecting custom SMTP, Supabase allows up to 30 emails per hour by default. Adjust this in your Supabase Rate Limits settings: Authentication → Rate Limits → Rate limit for sending emails

Ark Side

Ark has no hard rate limits. You’re billed per email sent at $0.50 per 1,000 emails. See billing for details.

Tracking Delivery

Every email sent through Ark is tracked. View delivery status in:

Ark Dashboard: arkhq.io/org/emails
API: GET /v1/emails with filtering
Webhooks: Real-time delivery notifications

Set Up Webhooks (Optional)

Get notified when auth emails are delivered, bounced, or fail:

Go to arkhq.io/org/webhooks
Add your endpoint URL
Select events: MessageSent, MessageBounced, MessageDeliveryFailed

Webhook Setup

Full webhook configuration guide

Troubleshooting

Emails not sending

Check these in order:

Domain verified? Check arkhq.io/org/domains
Credentials correct? Username format is org-name/credential-name
SMTP enabled? Toggle must be ON in Supabase SMTP settings
Credits available? Check arkhq.io/org/billing

Authentication failed

Symptoms: “535 Authentication failed” in Supabase logsSolutions:

Username is your credential name (e.g., acme/production), not your email
Password is the credential key, not your Ark account password
Check credential is active in dashboard

Emails going to spam

Causes: New domain, missing DNS records, or email content triggersSolutions:

Verify all DNS records are configured (SPF, DKIM, DMARC)
Wait 24-48 hours for domain reputation to build
Check email content doesn’t trigger spam filters
Ask recipients to mark emails as “not spam”

Connection timeout

Causes: Firewall blocking port 587, or network issuesSolutions:

Try port 465 instead of 587
Check firewall allows outbound SMTP
For serverless (Vercel, Netlify): SMTP should work, but consider REST API for edge functions

Rate limit errors from Supabase

Cause: Supabase’s internal rate limit, not Ark’sSolution: Increase the limit in your Supabase Rate Limits settings:Authentication → Rate Limits → Rate limit for sending emailsSet to a higher value (e.g., 100/hour for production apps).

Managing Your Connection

Verify Connection Status

Check your integration status at arkhq.io/org/integrations. You can:

Verify: Click the refresh icon to confirm the connection is active
View in Supabase: Link to your project’s SMTP settings
Disconnect: Remove the integration (resets Supabase to default email)

Disconnect

To disconnect Ark from your Supabase project:

Go to arkhq.io/org/integrations
Find your connected Supabase project
Click the disconnect button
Confirm the action

Disconnecting will reset your Supabase project to use the default email provider. Auth emails will revert to Supabase’s built-in SMTP with its rate limits.

Beyond Auth Emails

Once Ark is configured for Supabase auth, you can also use it for:

Transactional emails from your app (order confirmations, notifications)
User communications (welcome emails, onboarding sequences)
System alerts (error notifications, admin alerts)

Use the same credentials with our SDKs or REST API for non-auth emails.

Send with Node.js

npm install ark-email

Send with Python

pip install ark-email

FAQ

Will this affect my existing Supabase auth flow?

No. Ark only handles email delivery. Your auth logic, templates, and user flows remain unchanged.

Can I use different credentials for different Supabase projects?

Yes. Create separate credentials in Ark for each project. This lets you track emails per-project in your dashboard.

What happens if Ark is down?

Supabase will queue the email and retry. Ark has 99.9%+ uptime. Check status.arkhq.io for current status.

How much does this cost?

0.50 per 1,000 emails. New accounts get

5 free credit (~10,000 emails). Most auth-only apps stay within free tier. See billing.

Can I customize the email templates?

Templates are configured in Supabase, not Ark. Edit them in Authentication → Email Templates in your Supabase dashboard.

Next Steps

Set Up Webhooks

Get notified on delivery events

View Email Analytics

Track delivery rates in your dashboard

Send Transactional Emails

Go beyond auth emails

SMTP Reference

Full SMTP documentation

Overview

Languages

AI Integration

IDE Integrations

Platform Integrations

1-Click Setup (Recommended)

Manual Setup (5 minutes)

Domain Setup Guide

What Changes

Configuration Reference

SMTP Settings

Recommended Sender Addresses

Supabase Auth Email Types

Self-Hosted Supabase

Rate Limits

Supabase Side

Ark Side

Tracking Delivery

Set Up Webhooks (Optional)

Webhook Setup

Troubleshooting

Managing Your Connection

Verify Connection Status

Disconnect

Beyond Auth Emails

Send with Node.js

Send with Python

FAQ

Next Steps

Set Up Webhooks

View Email Analytics

Send Transactional Emails

SMTP Reference

Overview

Languages

AI Integration

IDE Integrations

Platform Integrations

​1-Click Setup (Recommended)

​Manual Setup (5 minutes)

Domain Setup Guide

​What Changes

​Configuration Reference

​SMTP Settings

​Recommended Sender Addresses

​Supabase Auth Email Types

​Self-Hosted Supabase

​Rate Limits

​Supabase Side

​Ark Side

​Tracking Delivery

​Set Up Webhooks (Optional)

Webhook Setup

​Troubleshooting

​Managing Your Connection

​Verify Connection Status

​Disconnect

​Beyond Auth Emails

Send with Node.js

Send with Python

​FAQ

​Next Steps

Set Up Webhooks

View Email Analytics

Send Transactional Emails

SMTP Reference

1-Click Setup (Recommended)

Manual Setup (5 minutes)

What Changes

Configuration Reference

SMTP Settings

Recommended Sender Addresses

Supabase Auth Email Types

Self-Hosted Supabase

Rate Limits

Supabase Side

Ark Side

Tracking Delivery

Set Up Webhooks (Optional)

Troubleshooting

Managing Your Connection

Verify Connection Status

Disconnect

Beyond Auth Emails

FAQ

Next Steps